Hundreds of polio teams are working in the area with many volunteers helping to eradicate polio, police official Naseebullah Khan said.

“Sakina Bibi, 50, and her 20-year-old daughter, Alizah, were providing polio immunisation drops to children when two gunmen riding on a motorcycle shot them. Both died on their way to the hospital,” said Khan.

In the past, there have been many attacks on polio teams, which are usually women.

Shahid Khaqan Abbasi, The Prime Minister of Pakistan has condemned the cowardly attack.

No organisation has claimed responsibility of the attack.

“Polio teams are rendering a huge national service to save our children from the crippling disease. Attack on these dedicated workers, risking their lives for their nation, is an attack on our future,” Abbasi’s office said in a statement.

Polio has been eradicated from all countries except Afghanistan, Nigeria and Pakistan.

Despite many threats from the Taliban, Regular anti polio campaigns are launched by the Pakistani government. The Taliban claim that these vaccines are not for polio but sterilise children and is a western agenda.

A colleague of the two women who did not wish to be named told the Guardian: “This is really tragic, that our colleagues have been killed in the line of duty in Quetta today. There may be various insights behind this incident but, for the national cause, government administration, security agencies and polio workers are still committed to keep campaigns continuing.”

Mahmood Jan, an Islamic cleric, said: “In Quetta and the surrounding districts of Balochistan, people fear espionage like [that carried out by] Shakil Afridi. People here mostly dislike NGO activities – polio being part of such activities.

“Currently, polio vaccination teams are guarded by police personnel. Hence scepticism of the high-profile campaign of the American agenda – and our government is promoting their agenda.”

Suspicion of vaccination drives was exacerbated by disputed reports that a Pakistani doctor used a fake hepatitis vaccination campaign to gather DNA samples to help the CIA track down Osama bin Laden.